X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=KernelLand%2FKernel%2Fvfs%2Fmemfile.c;fp=KernelLand%2FKernel%2Fvfs%2Fmemfile.c;h=14b39481d0c82d7adc503d605ace864855f27ead;hb=48743e39650eb1ef988380e9d95f27fd40d3a9ce;hp=0000000000000000000000000000000000000000;hpb=a2495c6ea4f4cab16b5d339ae511428e92e89e73;p=tpg%2Facess2.git

diff --git a/KernelLand/Kernel/vfs/memfile.c b/KernelLand/Kernel/vfs/memfile.c
new file mode 100644
index 00000000..14b39481
--- /dev/null
+++ b/KernelLand/Kernel/vfs/memfile.c
@@ -0,0 +1,135 @@
+/* 
+ * Acess 2
+ * Virtual File System
+ * - Memory Pseudo Files
+ */
+#include <acess.h>
+#include <vfs.h>
+
+// === PROTOTYPES ===
+tVFS_Node	*VFS_MemFile_Create(const char *Path);
+void	VFS_MemFile_Close(tVFS_Node *Node);
+Uint64	VFS_MemFile_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer);
+Uint64	VFS_MemFile_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, const void *Buffer);
+
+// === GLOBALS ===
+tVFS_NodeType	gVFS_MemFileType = {
+	.Close = VFS_MemFile_Close,
+	.Read = VFS_MemFile_Read,
+	.Write = VFS_MemFile_Write
+	};
+
+// === CODE ===
+/**
+ * \fn tVFS_Node *VFS_MemFile_Create(const char *Path)
+ */
+tVFS_Node *VFS_MemFile_Create(const char *Path)
+{
+	Uint	base, size;
+	const char	*str = Path;
+	tVFS_Node	*ret;
+	
+	str++;	// Eat '$'
+	
+	// Read Base address
+	base = 0;
+	for( ; ('0' <= *str && *str <= '9') || ('A' <= *str && *str <= 'F'); str++ )
+	{
+		base *= 16;
+		if('A' <= *str && *str <= 'F')
+			base += *str - 'A' + 10;
+		else
+			base += *str - '0';
+	}
+	
+	// Check separator
+	if(*str++ != ':')	return NULL;
+	
+	// Read buffer size
+	size = 0;
+	for( ; ('0' <= *str && *str <= '9') || ('A' <= *str && *str <= 'F'); str++ )
+	{
+		size *= 16;
+		if('A' <= *str && *str <= 'F')
+			size += *str - 'A' + 10;
+		else
+			size += *str - '0';
+	}
+	
+	// Check for NULL byte
+	if(*str != '\0') 	return NULL;
+	
+	// Allocate and fill node
+	ret = malloc(sizeof(tVFS_Node));
+	memset(ret, 0, sizeof(tVFS_Node));
+	
+	// State
+	ret->ImplPtr = (void*)base;
+	ret->Size = size;
+	
+	// ACLs
+	ret->NumACLs = 1;
+	ret->ACLs = &gVFS_ACL_EveryoneRWX;
+	
+	// Functions
+	ret->Type = &gVFS_MemFileType;
+	
+	return ret;
+}
+
+/**
+ * \fn void VFS_MemFile_Close(tVFS_Node *Node)
+ * \brief Dereference and clean up a memory file
+ */
+void VFS_MemFile_Close(tVFS_Node *Node)
+{
+	Node->ReferenceCount --;
+	if( Node->ReferenceCount == 0 ) {
+		Node->ImplPtr = NULL;
+		free(Node);
+	}
+}
+
+/**
+ * \fn Uint64 VFS_MemFile_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
+ * \brief Read from a memory file
+ */
+Uint64 VFS_MemFile_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
+{
+	// Check for use of free'd file
+	if(Node->ImplPtr == NULL)	return 0;
+	
+	// Check for out of bounds read
+	if(Offset > Node->Size)	return 0;
+	
+	// Truncate data read if needed
+	if(Offset + Length > Node->Size)
+		Length = Node->Size - Offset;
+	
+	// Copy Data
+	memcpy(Buffer, (Uint8*)Node->ImplPtr + Offset, Length);
+	
+	return Length;
+}
+
+/**
+ * \fn Uint64 VFS_MemFile_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
+ * \brief Write to a memory file
+ */
+Uint64 VFS_MemFile_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, const void *Buffer)
+{
+	// Check for use of free'd file
+	if(Node->ImplPtr == NULL)	return 0;
+	
+	// Check for out of bounds read
+	if(Offset > Node->Size)	return 0;
+	
+	// Truncate data read if needed
+	if(Offset + Length > Node->Size)
+		Length = Node->Size - Offset;
+	
+	// Copy Data
+	memcpy((Uint8*)Node->ImplPtr + Offset, Buffer, Length);
+	
+	return Length;
+}